It Is known to prepare homogeneous gels while using the so-called molecular imprinting technique by making imprints of dyes (R. Arshady, K. Mosbach; Makromol. Chemie, 182 (1981) 687) and amino acid derivatives (L. Andersson, B. Sellergren, K. Mosbach, Tetrahedron Lett. 25 (1984) 5211). Merely non-covalent bonding between a “print molecule” and monomers is used. After polymerisation of the monomers and removal of the print molecule, a selective polymer is obtained, based on binding groups correctly immobilised in space and present in cavities which have the shape of a mould of the print molecule. A summary of this technique is given by B. Ekberg, K. Mosbach, in Trends Biotechnol., 7 (1989) 92.
It is known to make imprints of carbohydrate derivatives substituted with covalently, but reversibly bonded vinylphenyl boric acid groups, so-called boronate esters, which after polymerisation have permitted hydrolysis and binding of a new print molecule (G. Wulff, ACS Symp. Series, 308 (1986) 186). Decisive of the selectivity of the thus prepared polymers are correctly positioned binding boronate groups and a well-shaped cavity. The drawback of this system is that a complicated chemical synthesis is necessary.
Prearranged boronate groups have also been used for Faking imprints of glycoprotein ((Transferrin, M. Glad, O. Norrlöw, B. Sellergren, N. Siegbahn, K. Mosbach, J. Chromatogr., 347 (1985) 11) and bis-nucleotides O. Norrlöw, M. O. Mánsson K. Mosbach. J. Chromatogr., 396 (1987) 374) on silica. In this context, use has been made of a mixture of non-covalently bonding organic silanes and boronate silane, which has been caused to interact with a print molecule before polymerisation on the surface. The effect of recognition seems mainly to depend on the fact that the boronate groups are correctly spaced from each other to be able to interact effectively with the print molecules. Transferrin has a total of four silica acid groups and bis-NAD has four riboses which form boronate esters.
It is also known to use, in affinity chromatography methods, adsorption material having specific ligands, but these are randomly localised on the sorbent and may therefore yield poor selectivity. Furthermore, there will be a large number of unused ligands, which is uneconomical from the industrial point of view.
Immobilised phenyl boric acid has been used to separate carbohydrate derivatives (H. L. Weith, J. L. Wiebers, P. T. Gilham, Biochemistry, 91 (1970) 4) and also to separate glycosylised hemoglobin and other glycoproteins (P. D. G. Dean, P. J. Brown, V. Bouriotis, U.S. Pat. No. 4,269,605 (1981).
For purification and analysis, especially of biological macromolecules, selectivity is most important. It is frequently necessary to distinguish a single component in a mixture of, maybe, several thousand components. The known adsorption materials are in most cases not sufficiently selective and cause non-specific binding, which may completely destroy the result of an analysis.
Modern biotechnical production and analysis as well as a large amount of medical diagnostics are based on selective binding. The methods known so far are also for these purposes not sufficiently selective and/or sufficiently simple to be economically useful on an industrial scale. Therefore there is a need of an adsorption material having very high selectivity and low non-specific binding, which may be prepared on a large scale and at low cost.